Waste asphalt blocks from construction sites are usually processed in the recycling plants to be used as recycled asphalt aggregates (RAA). At present, the RAA known as grizzly-under-materials (GUM) does not satisfy the required value for soil content, therefore it is used as roadbed materials. In 2009, a screenless piece of equipment was proposed to remove the soils from GUM, but it was necessary in 2013, to carry out a process of re-designing. This study shows a statistical analysis related to the effect of changing water content, temperature and clay, in soil reduction activity processing GUM with the newly screenless separation equipment. It was found that, from the point of view of statistics, difference arises in the equipment performance, when it was changed the soil contained in GUM and temperature, increasing the water content in the sample to process, besides, the highest difference was obtained changing soil, keeping constant temperature (15°C).